Assessment of 11kV Distribution Network for Power Loss Minimization using Analytical Technique for Capacitor Sizing

Abstract: The need to carry out a comprehensive assessment of 11KV distribution network for power loss has become inevitable. Unstable power supply from the grid could be as a result of instability and power losses in the transmission and distribution systems, which is unhealthy to the consumer’s power system operators, as well as power system equipment and operations. This work was done by carrying out load flow studies of the standing 11kV distribution network using embedded algorithm of Newton Raphson Method in ETAP Software; the losses were determined and minimized by the integration of capacitor banks (300kVar) in the critically overloaded buses and load flow was performed again. The results obtained indicates that three (3) out of the eighteen (18) distribution transformers were critically overloaded. The net real and reactive power losses are 57.92kW and 86.9kVar respectively. When reactive power was injected through capacitor banks into the system, the result shows that all the transformers and buses are better loaded, and the new net real and reactive power losses reduced to 46.18kW and 69.27kVar respectively. There is a 20% reduction in power loss and all the bus voltages fall within ±5% of nominal voltage as declared by IEEE.

Keywords: Active power, Reactive power, Power loss, Capacitor bank, Distribution network, ETAP Software